I have a assembly compiled in VB.NET that contains two operators:

Public Shared Operator =(quarterA As CalendarQuarter, quarterB As CalendarQuarter) As Boolean
    Return quarterA.StartDate = quarterB.StartDate AndAlso
        quarterA.EndDate = quarterB.EndDate AndAlso
        quarterA.Quarter = quarterB.Quarter
End Operator

Public Shared Operator <>(quarterA As CalendarQuarter, quarterB As CalendarQuarter) As Boolean
    Return Not (quarterA = quarterB)
End Operator

However, when using the assembly in C# to perform equality checks if (qtr != null) I receive the error:

Cannot implicity convert type 'object' to 'bool'

My original intent with the = operator was only for assignment purposes in VB, so I may be way off base (I don't use custom operators too often).

What do I need to do to make the operator behave with both equality and assignment operations?